i have a 79 stepside that i want to rebuild i know what i want i just don't know where to start?i'm thinking a total frame off but not sure yet.as far as the suspension i like to keep the same height but what can i do to tighten it up some i'm willing to give up some height but not alot.any help please.  

Just like building a house you got have a good founation to work on. If you don't want to change anything rebuild whats there. New king pins ( still twin I beem right?) New spring bushing and what ever else it needs. I have seen lowerd  twin I beems advertised in Trucking mag.  

Some good tips Curtis.